Big -- babble as they try to form their first words. And a new study shows that infants learned to talk not just by listening but also by looking. Researchers writing in the proceedings of the national academy of science say. That when babies -- the babbling staged they actually become slippery focusing their attention on the -- of speakers and -- master. The basic speech forms of their native language. The authors say this study could also help diagnose autism spectrum disorder earlier than now possible. They say that infants at risk for the disorder follow a different developmental path. In the one noted here so for most babies speeches in the -- as well as the year of the behold. With this medical minute. I'm doctor Timothy Johnson.

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